1. Field of the Invention
The present invention relates to a method of sticking film sheet on a panel surface and a laminator designed for this sticking operation.
2. Description of the Prior Art
There have been known in the prior art laminators used to stick film such as photosensitive dry film to the surfaces of the panels which are made of, for example, copper laminated glass epoxy board. In these laminators the film is pressure stuck in continuous film web form to the plurality of panels in turn, the panels being carried on a transfer means such as a roller conveyor. At the subsequent stage the panels thus jointed with the length of film web are separated into individual sheet film laminated panels by severing the film web at the points where each panel is connected thereby to the adjacent ones. However, these conventional procedures not only have demanded a great deal of time and labor in the finishing stage but also have caused a quantity of severed film to be wasted.
An improved laminator has been proposed to overcome the above-mentioned problems, as is described in Japanese Laid-Open Patent Application No. 52-14876. In this laminator a tacking means is provided to tack the leading end of the continuous web of film to the forward end of the blank panel which has carried over on the belt conveyor to the tacking station. The panel is then moved on the conveyor to pass together with the film web tacked thereon between a pair of pressure rolls adapted to pressure stick the film web on the surface of the panel. The operation of the belt conveyor and the pressure rolls are stopped when the panel moves a predetermined distance between the rolls. Then, the cutter severs across the film web to form a film sheet of predetermined length. The belt conveyor and the rolls are then restarted to complete pressure sticking of the separated film sheet on the panel surface. The severed end of the film web is tacked to the next panel and the same process is repeated. In this way, the individual film sheets are always cut from the continuous film web to just the required length matching the size of the panel and, accordingly, the extra finishing operation of trimming the film sheet on the panel involved in the prior art laminators is eliminated. Moreover, no waste of film as a result of cutting takes place.
However, this improved laminator presents a problem in the step of sticking the film sheet to the panel in itself. That is, as a result of temporary suspension of the sticking process while the film sheet is cut off from the film web, a linear roll mark tends to appear across the film sheet on the panel where the rolling operation has been stopped midway. This disadvantage prevents the production of film sheet laminated panels with uniform high quality.